Morphology and digitally aided morphometry of the human paracentral lobule

The human paracentral lobule, the junction of the precentral and postcentral gyri at the medial hemispheric surface, contains several important functional regions, and its variable morphology requires exact morphological and quantitativedata. In order to obtain precise data we investigated the morphology of the paracentral lobule and quantified its visible (extrasulcal) surface. This surface corresponds to commonly used magnetic resonance imaging scout images. We studied84 hemispheres of adult persons (42 brains; 26 males and 16 females; 20–65 years) fixed in neutral formalin for at least 4 weeks. The medial hemispheric surface was photographed at standard distance and each digital photo was calibrated.Using the intercommissural line system (commissura anterior-commissura posterior or CA-CP line), we performed standardised measurements of the paracentral lobule. Exact determination of its boundaries and morphological typeswas followed by digital morphometry of its extrasulcal surface using AutoCAD software. We found two distinct morphological types of the human paracentral lobule: continuous type, which was predominant (95.2%), and rare segmented type (4.8%). In hemispheres with segmented cingulate sulcus we also found theshort transitional lobulo-limbic gyrus (13.1%). The mean extrasulcal surface of the left paracentral lobule was significantly larger, both in males (left 6.79 cm2 vs. right 5.76 cm2) and in females (left 6.05 cm2 vs. right 5.16 cm2). However, even larger average surfaces in males were not significantly different than the same in females. Reported morphological and quantitative data will be useful during diagnostics and treatment of pathologies affecting the human paracentral lobule, and in further studies of its cytoarchitectonic and functional parcellations

Standardized Digital Mapping Of The Central Nervous System Connections In Humans Standardized Digital Mapping Of The Central Nervous System Connections In Humans

Abstract This paper attempts to unite different aspects of knowledge of both, human neuroanatomists and neuroinformatics engineers, related to the same problem of presentation of human brain connections. During the history, until to the end of twentieth century, presentations of the central nervous system connections or pathways in humans were related to technical and printing limitations, as well as to insufficient knowledge and data. Explosion of both, information technologies and neurosciences, caused fundamental changes of this almost traditional situation. Different presentations and different approaches in collecting neuroanatomical data resulted in very incoherent systems of data presentation about central nervous system connections, which situation itself became now additional limiting factor. In this paper we propose a standardized system of presentation, or better to say, of mapping of nervous pathways in geographical terms. In order to contain the maximum of information and to remain practical for use, here described system of presentations of connectivity data should be based on following principles: 1. presentation of one functional system by one basic colour; 2. exactly defined colour in RGB (red, green, blue) system for each of "neurons" in neuronal chain forming a pathway; 3. simplicity in visual presentation with several levels (magnifications) of details presentation; 4. design for use primary in computer systems, including the possibility of addition of new data (extensibility and adaptability). In creation of such readable representations that are capable to be updated effectively, aesthetics also should be considered. Several examples in mapping of motor, sensory and limbic pathways are presented. Also, problems present in creation of such one system are discussed, especially those related to neuroanatomical terminology, as well as possible solutions which offer new technologies

Microanatomical study of replaced meniscus in the rabbit.

We investigated clinical and morphological characteristics of replaced menisci after the transplantation of deep frozen meniscal allografts. We replaced medial menisci (in 18 New Zealand white rabbits) by meniscal grafts obtained fro m other rabbits. These grafts were kept in a deep f reezer (3-5 weeks), thawed in sterile saline and transplanted. The menisci were removed and studied after 2 weeks (first group), 8 weeks (second group) and after 36 weeks (third gro u p ) . Menisci from non-operated, contralateral knees served as controls. The tissue of the menisci investigated was processed using several histological and histochemical methods and analyzed by light microscope. Transplanted meniscal allografts retained a normal gross appearance, healed f i rmly through fibrovascular tissue to the re c i p i e n t capsular tissue, and did not show macro s c o p i c pathological changes. At the histological evaluation, in the first group the collagen fibers were i r regularly oriented, with a low cellular population. In the second group, blood vessels were p resent, cellular repopulation and immature collagen fibers being observed. The third group had a more mature collagen tissue, with a significant cell repopulation. Deep-frozen meniscal allografts showed significant collagen remodeling with cellular and vascular ingrowth from the surro u n d i n g synovia. This suggests that used allografts function normally and protect underlying cartilage

Correlation Between Tlp, Hmm, And System-Level Esd Pulses For Cu Metallization

Correlation factors between different ESD pulse types for different back-end-of-line (BEOL) metal-line topologies have been studied to support system-level on-chip ESD design. The component level (HMM, HBM, and TLP on a wafer) and system-level (IEC gun contact on package) ESD stresses were correlated followed by extraction of correlation factors between the IEC/HMM and TLP, as well as the HBM and TLP supported by analytical approximation. The major conclusions were verified using the thermal coupled mixed-mode simulation analysis. © 2013 IEEE

Characterization of NO

INTRODUCTION: The aim of this study was to determine the presence and distribution of nitric oxide (NO)-producing neurons in the rat corpus callosum (cc). MATERIAL AND METHODS: To investigate this aspect of cc organization we used nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry and neuronal NO synthase (nNOS) immunocytochemistry. RESULTS: Intense NADPH-d-positive (NADPH-d+) neurons were found along the rostrocaudal extension of the cc (sagittal sections). They were more numerous in the lateral cc and gradually decreased in the more medial regions, where they were very few or absent. The Golgi-like appearance of NADPH-d+ intracallosal neurons allowed dividing them into five morphological types: (1) bipolar; (2) fusiform; (3) round; (4) polygonal; and (5) pyramidal. The number of NADPH-d+ neurons (both hemispheres) was counted in two brains using 50-μm thick sections. In the first brain, counts involved 145 sections and neurons were 2959; in the second, 2227 neurons were counted in 130 sections. The distribution and morphology of nNOS-immunopositive (nNOS(IP)) neurons was identical to that of NADPH-d+neurons. Some of these neurons were observed in the cc ependymal region, where they might be in contact with cerebrospinal fluid (CSF), monitoring its composition, pH, and osmolality changes, or playing a role in regulating the synthesis and release of several peptides. The somatic, dendritic, and axonal processes of many NADPH-d+/nNOS(IP) neurons were closely associated with intracallosal blood vessels. CONCLUSIONS: Such close relationship raises the possibility that these neurons are a major source of NO during neural activity. As NO is a potent vasodilator, these findings strongly suggest that NO-positive neurons transduce neuronal signals into vascular responses in selected cc regions, thus giving rise to hemodynamic changes detectable by neuroimaging